Arc-light cluster



M. MAYER.

ARC LIGHT CLUSTER.

APPLICATION FILED NOV. 20, 1920.

1 ,409, 1 91 I Patented Mar 14, 1922.

moms in Arc-Light Clusters,

MAX MAYER, OF NEW YORK, N. Y., ASSIG-NOR TO 111. J. WOHL & 00., INC., LONG ISLAND CITY, NEW YORK, A CORPORATION OF NEW YORK.

ARC-LIGHT CLUSTER.

Application filed November 20, 1920.

Z 0 all whom it may concern -Be it known that I, Mm: Marian, a citizen ofthe. United States, and residing in the city, county, and State of New York, have invented certain new and useful Improveot which the following is a specification.

This invention relates to improvements in electric arc light-clusters and especially to that type commonly known as top lights in which the light of a suspended arc lamp is downwardly reflected and diiiused by a transparent mediumsurrounding the lower 'partot the lamp, to provide uniform illumination of objects below the lamp, principally tor photographic purposes.

It is the particular object of the present invention to provide a cluster are lamps which combines a maximum ot evenly dittused light in a minimum of space It is another object o't the invention to provide a top light cluster which isadiqitcd to accommodate a plurality 01: are lamps of standard design, lamps which also may be used for horizontal projection or similar purposes, and to make these lamps instantly available for such different use.

It is a further object of the invention to provide a top light cluster which permits variation of light emissioirwithina wire range, without special apparatus and with a minimum of current consumption,

WVith these and other objects in view the invention consists of a novel arrangement of parts and details of construction hereinafter fully described and illustrated in the accompanying drawings, which form a part of these specifications and as finally pointed out in the claims.

On the drawings: I

Fig. 1 is a sectional plan of the top are light cluster on the line 1-1 of Fig. 2.

Fig. 2 is a front elevation of the cluster partly in section on the line 22 of ig. 1.

Fig. 3 is a detail showing the hook 123 in elevation.

Fig. 4 is a detail sectional elevation through the diffuser 40.

Fig. 5 is a sectional plan on the line 55 of Fig. 4.

Fig. 6 is a detail elevation showing a central section of the top of reflector 30 in large .SCale', I I

Specification of Letters Patent.

Patented Mar. 14, 1922. Serial No. 425,431.

Fig. 7 is a sectional detail of box 20 on the line 77 of Fig. 6.

Similar characters of reference indicate corresponding parts throughout the various Referring to Fig. 2 of the drawings 1 is a central tube suitably suspended from the ceilin of a room by means of a cap 2, insulating roller 3 and S shaped hook 4. On cap 2 is held by means of brackets 5 a horizontal rectangular frame consisting of parallel bars 6 and 7 which acconm'iodate 4: pairs 01 two pulleys 8 turning freely on pins 9 in the open space between these bars. On each pair of pulleys a duplex arc lamp 10 is suspended by means of a rope or chain 11 and counterweight 12. The are lamps 10 are fastened to rope 11 by means of a specially tormed S hook 13 shown in detail in Fig. 8 provided with two complete rings of which the lower one acconuuodates the usual insulating roller and the upper-one remains tree topermit the passing of the horizontal rods 1% therethrough. The inward ends 01 these rods are removably held in a,i)ertures ot a collar 15 to which they may be fastened by screws 16, this collar 15 is slidably mounted on the central tube 1 to which itmay be clamped by means of a hand screw 17. To the lower end of tube 1 a large reflector 30 forming the frustum of a cone is fastened by means or" two nuts 18 and 19 whose threads engage the tube 1. The lower end of tube 1 holds by means of a male thread a box-like cap 20 provided with a central aperture detail shown in Figs. 6 and '7) through which a vertical rod 21 glides, the upper end of this rod is provided with a piston 22 to guide the rod within the tube 1 and to form a stop for the same. The lower end of rod 21 carries a difi'user 4:0 in form '01" an inverted cone, by means of nut 26 forming a knob for the rod 21. Rod 21 is also equipped with an angular pin 23, suitably placed, which may enter the cap 20 through slot 2-1 and be rotated in the same at'ter entering, until the downwardly directed part of the pin drops into a suitable aperture and locks the rod 21 in the cap 20. The reflector is preferably made of sheet metal, its horizontal part is provided with four apertures through which the arc lamps 10 may enter from above, and consists of two parallel circular plates 31 and 32, each aperture holds a short flanged vertical tube 33 whose horizontal flange is held in the space between the plates 31 and 32 and electrically welded thereto. The upper ends of tubes 33 are bent outwardly to form a rim 34 around "each tube. The supporting plate 50 of the v lamp mechanism in proper position on the reflector; plates 31 and 32 are provided with a number ofventilating apertures 37 whiph are covered by light shades 35. When lamps 10 are raised into the elevated position shown by dash and dotted lines of Fig. 2 the tubes 33 are closed by means of a cover 36. The conical side of reflector isheld between flanges of plates 31 and 32 and provided with four preferably hinged doors 38, in radial alinementwith each lamp to facilitate trimming.

The conical diffuser 40 consists of two basket-like frames placed into eachother and made of channel shaped moldings as 7 shown in Figs. 4 and v5; 41 and 42 are cup shapedmembers which rest on nut26. They support the upright bars 43 arranged parallel to the surface of the diffuser cone and moldings 44.

are joined by hoops '45 and cross section.

fitting into corresponding U shaped metal The upper ends of each set of uprights 46 of the same Between the inner basket frame 4143-45 and the outer frame 4244--46 a sheet of woven glass fabric 49 is placed and the frames tied againsteach otherby means of screw 47 and thetwi'sting of the wires'48 to clamp and stretch the glass fabric within the conical frames.

" This are light-cluster may be used to vary the illumination it provides within wide limits, which is of particular value for photographic purposes. The are lamps used therein are preferably duplex arc lamps having one mechanism for two arcs in series on a 125 volt circuit, a type which is in general use in photographic studios as an illuminating-unit. These'lamps are easily fastened by'means ofhook 13 to the ropes 11 of the clusterand are then individually movable intoand out of the reflector 30 providing the rods 14 are removed from collar. 15, the counterweights 12 holding the lamps balanced at any desired elevation. v In this manner 2, 4, 6 or 8 arcs may be used simultaneously by providing a switch for each lamp. The lamps not in use may be held above the reflector in the position shown in dotted lines in Fig. 2, where they can be lit to give a general illumination besides the specific one from the lamps in the reflector, or they may be removed entirely and put to a different taneousl'y.

use in the studio. By inserting the rods 14 through the rings of hook 13 into the collar .15 and fastening screws 16, two, three or four lamps can simultaneously be operated vertically and'held in desired position by turning hand screw17. It'may be remarked that the it can be entirely removed from the clusterif a strong direct illumination is desired-by unscrewing cap 20 from nut 19.,

In this manner it is possiblewithout the use of dimming resistances or loss of current to vary the illumination from a. dim diffused light-by using only, one lamp. and the diffuser.to an extremely strong direct light.

by using eight arcs within a single reflector without the diffuser and such'change'ca'nbe effected in steps asiwell as almostlnstan- Having thus described my invention what I claim as new and desire to secureby Let- 'ters Patent is: r

1'. In a'device of the kind described acentral'support adaptedto be suspendedon its upper end, a reflector held on the lower end thereof, a plurality of apertures in said re flector, arc lamps adapted to enter said 1 er.-' tures, an annular ring slidably mountec on said support and arms on said ringforming means for the suspensionofisaid lamps.

2.;In adevic'e of the kind described, a centrai support adapted to be suspended on its upper end, a reflector surrounding said support attached near the lower endthereof', an annular ring slidably mounted on said support, a plurality of radial arms on said ring, are lamps depending from said arms through aperturesin said reflector, said are lamps forming removable covers for :said apertures. 7

3. In a device of the kind described, a plurality of arc lamps surrounding a common support, said support having means adjustable to vary the vertical position of the lamps, a reflector in concentric alinement with said support, an aperture for-each lamp in said reflector permitting a partof said lamp to protrude into said reflector'and means on each of saidlamps for its central alinement within said aperture. 7

4. In a device of the kind described, a dif fusion screen consisting-of abowl shaped frame, being composed of a supporting hub, a ring held above said hub forming the circumference of said screen and channel' shaped radial arms connecting said hub to said ring, a sheet of translucent fabric on said frame and clamping means in the channels of said arms to fasten said fabric to said frame.

5. In a device of the kind described, a central tube surrounded by a plurality of lamps, a reflector above said lamps, a cap on said tube to support said reflector, a rod holding ,a diffuser at its lower end slidably and rotatively mounted in said tube, a pin on said rod adapted to enter said cap forming means to support and to lock said difi'user in elevated position by a rotative movement of said diffuser Without access to the interior portion thereof.

6. In a device of the kind described, a diffusing screen consisting of two similar bowl shaped frames fitting into each other, each frame being composed of a supporting hub and a ring held above said hub forming the circumference of said screen, and radial arms connecting each hub to its ring, a sheet of translucent fabric inserted between said frames and means ;to clamp said frames against each other to hold said sheet. v

7. In a device of the kind described, a central support adapted to be suspended on its upper end a plurality of arc lamps movably attached to said support, a reflector surrounding said support provided with apertures permitting said lamps to enter said reflector and separate counterbalancing means for each arc lamp to hold all of said lamps at different elevations.

8. In a device of the kind described, a central support adapted to be suspended on its upper end a plurality of arc lamps movably attached to said support, a reflector surrounding said support provided with apertures permitting said lamps to protrude into said reflector, counterbalancing means for said are lamps, and means to hold all of said lamps at the same elevation and inbalanced condition.

9. In a device of the kind described, a central support adapted to be suspended on its upper end, a plurality of arc lamps movably attached to said support, a reflector surrounding said support provided with apertures permitting said lamps to protrude into said reflector, counterbalancing means for said arc lamps and means to move a number of said lamps simultaneously and permitting to move other lamps singly in balanced condition.

10. In a device of the kind described, a central support adapted to be suspended on its upper end, a reflector and a diffusing screen concentrically held by said support, a plurality of arc lights arranged in pairs enclosed by said reflector and said screen, means to permit the removal of each pair of lights separately from said reflector and means on said support to hold said lights in elevated position above said reflector.

11. In a device of the kind described, the combination with a reflector adapted for ceiling suspension and provided with a plurality, of apertures surrounding a common center; of lamps adapted to enter said apertures, supporting means above said reflector to hold said lamps in alinement with said apertures, and means to vary the vertical position of said lamps.

12. In a device of the kind described, the combination with a reflector adapted for ceiling suspension and provided with a plurality of apertures surrounding a common center; of lamps adapted to enter said apertures, supporting means above said reflector to hold said lamps in alinement with said apertures, and counterbalancing means to vary the vertical position of said lamps.

13. In a device of the kind described, the combination with a reflector adapted for ceiling suspension and provided with a plurality of apertures surrounding a common center; of lamps adapted to enter said apertures, supporting means above said reflector to hold said lamps in alinement with said apertures, means to vary the vertical position of said lamps and-means to hold all of said lamps in horizontal alinement. 7

14. In a device of the kind described, the combination with a reflector adapted for ceiling suspension and provided with a plurality of apertures surrounding a common center; of lamps in alinement with said apertures, means to hold some of said lamps at the same vertical elevation and means permitting a variation of the. vertical position of one or more other lamps.

MAX MAYER. 

